Drill-steel retainer



G. G. TUTTLE.

DRILL STEEL RETAINER..

APPLICATION FILED IuNEz, 1921.

Igf, Patentedept 19, 1922o "4 umm I II 1 I j V' 5 Z I I HIS ATT'o NEY daaraan. narran, or rnraarrsenae, new teaser, instancia re ananas-canarino' enr orar, new anni?, a oonronarron or new sanear.

mi (al Git',

aanneemt. asesinan.

Application hled June 319221. Serial No. 474,41'36.

Toall whom t cof/wem: v

Be it .hewn that l, Gnovnn G. TU'rrLn, a citizen oi the United States, and a resident of Phillipsburg, Warren County, State of New derse have invented. a certain Drill- Steel Retainer, of which the following is a specication accompanied by draw1ngs.

This invention relates to-drillsteel retainers for rock drills, but more particularly' to that type of retainerin which a yoke einbraces the drill steel and is suitably held or clamped in position upon the front head of th'e machine. y l n Such yoke retainers are subjected to severe impact as the collar on the drill steel strikes the yoke and various devices have been employed to cushion or yieldingly hold the yoke to avoid breakageo the partfspsomeot these devices including bolts and springs, but the breakage is diigcult to "overcome, and the more complex the parts, the greater the danger of breakage becomes.

The primary objects of. the present invention are to simplify the retainer construc= tion, and reduce the chances of breakage by avoiding the use' of retainer bolts and supporting the yoke retainer trom the front head of the machine by means of an arrangement of main and supplementary 'sprlngs which cushion the'yoke in both directlons.

Another object of the invention is to sups pleinent the expansive force or' the main springs in holding the retainer, by meansot huid under pressure, which may be the live pressure takenfroin. the supply inlet of the machine. lln' such case, it the pressure tails for any reason, the main retainer springs still fulfill the function of exerting pressure to cushionV the oke.

Another object o the invention is to make thecasings for the springs separate from the iront head and mount' them to swing` relatively to the front head, carrying the yoke retainer with them. rll`his avoids the necessity of pivoting the yoke -retauner to the spring caslngs and permits a slmpler connection between the retainer and the spring casings. l

To these ends the invention is shown' 1n its preferred forms in the accompanymg drawings, in which I Figure l is a diagrammatic front elevatlon e which the drill steel D of the front head of a rock drill having my drill steel retainer applied thereto, partsof the front head and retainerjbeing shown in vertical section,

Figure 2 is a side elevation oi thel device in longitudinal section, and

Figure 3 is a horizontal sectional plan view of F1gure l on the line 33.v

Referring to the drawings, A represents 'head is provided ywith' the usual lugs F through which the side bolts G extend ior clamping the cylinder and iront head together. ln this instance the front end portion H of the cylinder casingis shown digrammatically and partly broken away to indicate the relation of the parts.

ln accordance with my invention the front head is provided with cushion' holding guides d -pivoted at 'opposite sides of the machine and main cushioning means in the form of coiled springs K are guided and held within said guldes J. ln order to suitably pivot the guides d so that they may swing at each side of the front head, the said front head is conveniently provided withftrunnions L and the guides d are formed with'bosses or bearing portions O formingsockets for the trunnions L. F or purposes hereinafter to appear, leather washers P are preferably arranged between the socket portions of the guides and the front head and underneath the caps Q, which-` are secured to the trunnions as by means of the screws R thus orming airtight joints around the trunnions. Spring pressed pins or detente S in' the trunnions are adapted to cooperate with the notches 'l in the socket pieces for centerin and maintaining the guldes in longitudina position except when moved out of said position. f

A yoke retainer U for the drill steel is provided with arms V ided in the spring holdin guides J and slidable longitudinally in sai guides. The Shanks or arms V of the yoke extend through the necks W oi the guides and cup leathers or washers of any suitable material Xiare seated over the yoke arms in the bottoms of the recessed portions Y of the guides. The main springs K, preferably coiled springs, surround the yoke arms, and caps Z 'are preferably placed over the springs to act as bearings. Cup leathers a or washers of any suitable material are placed over the caps Z and nuts b over .the Washers c are secured to the lends of the boltsvand retained in position as by means of suitable Cotter pins d. Supplementarysprings e are preferably coiled. over the to be held between the shoulders f of the guides, and washers g vbearing on the stops 'or collars h formed on the yoke arms V.

.Fluid pressure passageways j extending through the cylinder casing Hand through thefront head A of the machine are adapt#l ed to communicate with theinterior of the hollow socket portions Y of the cushion holding uides J and supplement the eX- pansive orce of the main springs K.

In the operation of the device it will be obvious that the yoke retainer may be swung into and out of retaining position about the trunnions L in which case theventire spring uides and yoke pivot about the tru-nnions. en the yoke is in retaining position the main springs K resist the blows of the collar E of the drill steel against the yoke, and the supplemental springs e resist pressure in the opposite direction and' serve to re.

tract the yoke.l The main springs are entirely enclosed and protected in the-guidesl and the upward pull of the yoke arms is resisted by the stops h forming collars on said arms integral -therewith which are not liable to becomeV broken. The packing in the form of Washers P and cup leathers X and a effectively seal the chambers formed within the recessed portions of the guides J so that the air pressure, preferably live air, admitted to said chambers tends tol assist the expansive force of the main springs K although if these springs are made sufficiently strong they will accomplish their purpose 'without the assistance of compressed air.

The air, however, isa valuable adjunct in a device of this character.

I claim:

1. A drill steel retainer for rock drills, comprising cushion holding -guides pivoted atopposite sides of the front head of the machine, cushioning means on said guides, a yoke retainer for vthe drill steel having arms guided in said guides and cushioned by said lcushioning means, and means for maintaining fluid pressure within said guides yto supplement the expansive force ofthe cushioning means in one direction. f 2. drill steel retainer for rock drills comprising spring holding guides pivoted at opposite sidesv of the front head of the machine, coiled springs held on said guides, a yoke retainer for the drill steel having arms guided in said guides and cushioned by said springs, -and means for maintain-ing fluid l pressure -within said guides to supplement the expansive force of the cushioning means in one direction.

3, drill steel retainer for rock drills, comprising spring holding guides pivoted at opposite sides of the front head of the machine, coiled springs held on said ides, a yoke retainer for the drill steel having arms slidable longitudinally in said guides and cushioned in both directions by springs, and

means for maintainin fluid pressure within said guides to supp ement the expansive for cushioning the yoke in the opposite direction, and means formaintainingl fluid pressure within said guides to supplement the expansive force of the cushioning means in one direction.

vsprings between said stops and the guides In testimony whereof I have signed this I specification.

GROVER G. TUTTLE. 

